1. Field of the Present Invention
The present invention relates generally to computing processing and, more particularly, to a method and system for improving initialization and synchronization of display devices to audio data.
2. Description of the Related Art
A data stream transmitted on interfaces for display receivers, such as High-Definition Multimedia Interface (HDMI), DiplayPort, S/PDIF, etc., embeds audio format metadata. When the data stream starts, it can take the display receivers in the order of half a second after the stream starts to detect the audio format metadata (such as sample rate) embedded in the data stream, to initialize, and to synchronize with the data stream. During this initialization time, the audio data is discarded, which can produce clipping of audio sounds. This can be especially notable for short system event sounds.
Current implementations to avoid the problems discussed above are for the interface to always carry “Keep Alive” silent audio data stream in the format of the latest data stream. In other words, a transmitter of the data stream can send a silent audio data stream in the latest format when no data stream is to be sent to the display receiver. Therefore, the display receiver does not need to re-initialize when the data stream re-starts. In order to save dynamic random access memory (DRAM) access power, the silent audio data stream is not generated by a CPU and streamed from system memory, rather it is generated on the interface encoder. An audio driver controls the “Keep Alive” feature.
However, in a system employing a display connected to a wireless receiver, a wireless transmitter is employed to send the data stream over a wireless link to the wireless receiver. The wireless receiver is connected to the display receiver to direct the data stream to the display receiver. In this system, the use of the silent audio data stream sent over the wireless link is both bandwidth and power inefficient. For example, depending on the audio format, a regular audio silent stream would take several or tens of Mbits/s of valuable wireless network bandwidth for no actual data content. Also, especially for mobile wireless audio or audio/video transmitters and receivers, the encoder of the transmitter would have to spend the power to generate regular but zeroed audio packets in the last format and send them to the radio transmitter. The radio transmitter would have to wake up and spend the radio power to send them, and the radio receiver would have to spend the power to send them to the interface encoder. Some aspects of these shortcomings are also present in the wired systems described above. These implementations are inefficient and power and bandwidth consuming.